1. Field of the Invention
The present invention relates to a universal joint.
2. Description of Related Arts
A coupling structure between a universal joint and a shaft is applied to a steering apparatus for an automobile, for example. In the steering apparatus, a steering shaft having an end connected to a handle and a pinion shaft of a steering mechanism are connected to each other through an intermediate shaft. Universal joints are respectively provided at both ends of the intermediate shaft. A yoke in the universal joint is coupled to a shaft end corresponding thereto.
For example, the yoke in the universal joint has a fitting portion in a U shape. The end of the steering shaft is fitted into the fitting portion. A bolt penetrates the fitting portion of the yoke at an end on the opening side of the U shape, and is screwed into a nut, so that the end of the steering shaft is fastened from both of its sides.
A cover mounted on a nut for covering the nut is known (see Document 1: Japanese Utility Model No. 3023464, for example).
In a case where the above-mentioned coupling structure is arranged in the interior of a crew compartment of an automobile, however, a foreign material such as a carpeting fiber in the crew compartment is liable to adhere to and accumulate on a nut and a locking portion in the vicinity of the nut for locking the nut. When the foreign material accumulates on the nut and the like, it takes time and labor to make maintenance.
In order to prevent the adhesion of the foreign material, therefore, it is considered that the cover in the foregoing document 1 is mounted on the nut.
Since the cover can only cover the nut, however, the foreign material cannot be prevented from adhering to and accumulating on the locking portion around the nut. Further, in the cover disclosed in the document 1, a plate spring for fixing is required. Therefore, the number of components is increased, so that the manufacturing cost rises.
An object of the present invention is to provide a universal joint capable of preventing a foreign material from adhering to a nut and the like and being low in cost.